| 1. |
- Froberg, A, et al.
(författare)
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Force in the achilles tendon during walking with ankle foot orthosis
- 2009
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Ingår i: The American journal of sports medicine. - : SAGE Publications. - 1552-3365 .- 0363-5465. ; 37:6, s. 1200-1207
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Tidskriftsartikel (refereegranskat)abstract
- Ankle foot orthoses are used for postoperative treatment of Achilles tendon ruptures and decrease calf muscle electromyography activity during walking. Hypothesis Achilles tendon load decreases with increased restriction of dorsiflexion and is associated with decreased triceps surae activity. Study Design Controlled laboratory study. Methods In 8 subjects, the maximum force and rate of force development in the Achilles tendon were measured with an optic fiber technique, and the activity of the gastrocnemius, soleus, and tibialis anterior muscles was recorded using electromyography. Trial conditions were walking barefoot and wearing an ankle-foot orthoses set in 3 different positions: (1) locked at 20° of plantar flexion and with free plantar flexion but restricted dorsiflexion to (2) 10° plantar flexion and (3) 10° dorsiflexion, respectively. The design of the ankle foot orthoses did not provide heel support when fixed in a plantarflexed position. Results Maximum Achilles tendon force was highest at the ankle-foot orthoses setting of 20° plantar flexion (3.1 times body weight) and decreased to 2.1 times body weight during barefoot walking ( P < .01). The rate of Achilles tendon force showed an increasing trend with less-restricted dorsiflexion. Soleus activity was 52% of mean barefoot walking activity at 3 20° plantar flexion ( P < .001) and then increased as dorsiflexion was less restricted. Conclusion Weightbearing in ankle-foot orthoses when dorsiflexion is restricted beyond neutral may result in increased forces in the Achilles tendon compared with barefoot walking, despite reduced electromyography activity in the triceps surae and decreased rate of force development. Clinical Relevance If patients bear full weight in an ankle-foot orthoses locked at 20° plantar flexion without heel support, the maximum force in the tendon may exceed that encountered during barefoot walking.
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| 2. |
- Gardin, A, et al.
(författare)
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Magnetic resonance signal, rather than tendon volume, correlates to pain and functional impairment in chronic Achilles tendinopathy
- 2006
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Ingår i: Acta radiologica (Stockholm, Sweden : 1987). - : SAGE Publications. - 0284-1851 .- 1600-0455. ; 47:7, s. 718-724
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To depict abnormal tendon matrix composition using magnetic resonance imaging (MRI) in chronic Achilles tendinopathy, and correlate intratendinous signal alterations to pain and functional impairment. Material and Methods: MRI of the Achilles tendon was performed on 25 patients with chronic Achilles tendinopathy (median age 50, range 37–71 years). All patients suffered from pain in the mid-portion of the Achilles tendon. Intratendinous signal was calculated from five different sagittal sequences, using a computerized 3D seed-growing technique. Pain and functional impairment were evaluated using a questionnaire completed by patients. Results: Severity of pain and functional impairment correlated to increased mean intratendinous signal in the painful tendon in all MR sequences ( P<0.05, median r = 0.38, range 0.28–0.43 for pain; P<0.05, median r = 0.48, range 0.29–0.49 for functional impairment). However, tendon volume did not correlate to pain or functional impairment ( P>0.05). Difference in mean intratendinous signal between symptomatic and contralateral asymptomatic tendons was highly significant in all sequences ( P<0.05) except on T2-weighted images ( P = 0.6). Conclusion: Severity of pain and disability correlated to increased MR signal rather than to tendon volume in patients with unilateral mid-portion chronic Achilles tendinopathy.
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| 3. |
- Liden, M, et al.
(författare)
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A histological and ultrastructural evaluation of the patellar tendon 10 years after reharvesting its central third
- 2008
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Ingår i: The American journal of sports medicine. - : SAGE Publications. - 1552-3365 .- 0363-5465. ; 36:4, s. 781-788
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Tidskriftsartikel (refereegranskat)abstract
- This study was undertaken to evaluate the histologic and ultrastructural characteristics of the patellar tendon 10 years after reharvesting its central third. Hypothesis In the long term, after its central third is reharvested, the patellar tendon does not regain a normal histological and ultrastructural appearance. Study Design Case-control study; Level of evidence, 3. Methods Twelve consecutive patients (4 women, 8 men) who underwent anterior cruciate ligament revision surgery using reharvested ipsilateral patellar tendon autografts were included in the study. Percutaneous biopsy samples were obtained from the central and lateral parts of the patellar tendon under ultrasonographic guidance at a median of 116 months (range, 102–127 months) after the revision procedure. Eleven biopsy specimens from asymptomatic patellar tendons obtained from open anterior cruciate ligament reconstructions served as controls. The histologic characteristics and the presence of glycosaminoglycans were assessed using a light microscope, and the ultrastructure was assessed using a transmission electron microscope. Results The histological evaluation revealed deterioration in fiber structure, increased cellularity, and increased vascularity in both the central and peripheral parts of the reharvested patellar tendon specimens compared with normal tendon specimens. No difference in the amount of glycosaminoglycans was seen in specimens from either part of the reharvested patellar tendons and the control specimens. The ultrastructural evaluation revealed that all the control specimens had a normal morphologic appearance and a compact extracellular matrix with regularly oriented collagen fibrils. Furthermore, in the control specimens, the fibril diameter was heterogeneous, with all fibril size classes present. Specimens from the central and the lateral part of the reharvested tendon displayed pathological cell appearance and a more heterogeneous extracellular matrix. The lateral specimens from the reharvested tendons also displayed all fibril size classes but with a more homogeneous distribution. In the central specimens, the largest fibril size class was absent. Conclusion Ten years after its central third was reharvested for anterior cruciate ligament revision surgery, the patellar tendon had not normalized in terms of its histological and ultrastructural appearance.
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| 6. |
- Movin, T, et al.
(författare)
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Intratendinous alterations as imaged by ultrasound and contrast medium-enhanced magnetic resonance in chronic achillodynia
- 1998
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Ingår i: Foot & ankle international. - : SAGE Publications. - 1071-1007 .- 1944-7876. ; 19:5, s. 311-317
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: We performed a comparative study of ultrasonography and gadolinium imaging contrast-enhanced T1-weighted magnetic resonance to evaluate tendon pathology in chronic Achilles tendon disorder. Another main issue was to evaluate the structural basis as defined by histopathology from hypoechoic compared with normoechic areas within the same tendon. Materials and Methods: Twenty patients (16 male, 4 females, median age 40 years) with chronic achillodynia participated in the study. Clinical examination revealed swelling and tenderness localized to the midportion of the Achilles tendon. Contrast medium-enhanced magnetic resonance imaging (CME-MRI) was performed in all patients. Ultrasonography-guided core biopsies were taken from regions with a clear widening of the tendon and a pathologic low-echo signal as well as from normoechoic areas. The specimens were analyzed with a standardized protocol giving a total tendon score (0–24), and a stereologic method for quantification of glycosaminoglycan (GAG)-rich areas. Results: The volume of the intratendinous abnormality was larger in 13 of 20 when imaged by CME-MR ( P < 0.05), whereas the shape and enlargement of the tendon per se were similarly imaged by ultrasound (US) and CME-MR. Tendon pathology as imaged by US was graded as severe from hypoechoic regions and moderate from normoechoic regions. The corresponding quantification of GAGs was 0.36 compared with 0.17, respectively ( P < 0.001). Conclusion: CME-MR imaging revealed greater sensitivity in demonstrating intratendinous pathology than the ultrasound; this was documented by the larger size of the corresponding lesion and the fact that the pathology was occurring in areas that were considered normal by ultrasonography. US hypoechoic areas showed a markedly abnormal tendon structure including an increased amount of GAG-rich areas. However, moderate pathology was also found in the neighboring normoechogenous areas within the same tendon, indicating a more generalized disorder than depicted by echogenic properties.
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| 7. |
- Movin, T, et al.
(författare)
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MR imaging in chronic Achilles tendon disorder
- 1998
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Ingår i: Acta radiologica (Stockholm, Sweden : 1987). - : SAGE Publications. - 0284-1851 .- 1600-0455. ; 39:2, s. 126-132
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: the primary objective was to compare 4 imaging sequences (T1-weighted, T2-weighted, proton density, and T1-weighted with gadolinium contrast agent enhancement) with regard to intratendinous signal abnormality in patients with achillodynia. the secondary objective was to relate the images to the clinical symptoms and histopathological findings Material and Methods: Twenty patients (16 men, 4 women, median age 40 years) with chronic achillodynia participated in the study. the symptoms prohibited activity and clinical examination revealed swelling and tenderness 1.5–6 cm proximal to the Achilles tendon insertion. of the 20 patients: 5 had bilateral achillodynia, 4 had had previous contralateral Achilles tendon disorder, and 11 had never had symptoms in the contralateral tendon region. These 11 tendons served as controls for comparison MR imaging was performed on a superconductive 1.5 T unit. Both Achilles tendons were examined (n=40) at the same time, and multiple sagittal and transversal images were obtained. the corresponding sections on these images were visually graded according to both extension and level of MR signal intensity. Tissue was obtained for microscopic examination from the most symptomatic side in all patients (n=20) Results: T1-weighted images following gadolinium contrast medium enhancement proved to be the best method by which to visualize intratendinous signal abnormality. This sequence revealed signal abnormality in 24/25 symptomatic tendons and in 1/11 control tendons ( p>0.001). Histopathological examination showed an increased noncollagenous extracellular matrix and altered fiber structure in the lesions corresponding to the contrast-enhanced areas Conclusion: Gadolinium enhancement improved the imaging of intratendinous signal abnormality on T1-weighted images. There was a high level of extracellular glycosaminoglycans, which are highly-fixed negatively-charged macromolecules with extreme water-retaining capacity and which may have contributed to the enhancement by the gadolinium contrast agent
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| 8. |
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| 9. |
- Shalabi, A, et al.
(författare)
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Dynamic contrast-enhanced mr imaging and histopathology in chronic achilles tendinosis. A longitudinal MR study of 15 patients
- 2002
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Ingår i: Acta radiologica (Stockholm, Sweden : 1987). - : SAGE Publications. - 0284-1851 .- 1600-0455. ; 43:2, s. 198-206
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To evaluate the value of dynamic contrast-enhanced MR imaging (DEMRI) and its correlation to symptoms and histopathology in chronic Achilles tendinosis. Material and Methods: Fifteen patients with severe symptoms underwent DEMRI preoperatively and 2 years postoperatively. US-guided core biopsies of tendinosis tissue were obtained preoperatively and the specimens were analyzed using a semiquantitative protocol. DEMRI was evaluated by calculating the area under curve (AUC) of signal alteration and the static MR by a semiquantitative grading scale. A questionnaire and clinical examination evaluated the clinical outcome. Results: Early contrast enhancement (first 72 s) was seen in DEMRI at tendon lesions of the symptomatic Achilles tendons with a significant difference to asymptomatic contralateral tendon that revealed no or mild enhancement. Increased severity of tendon pathology (including fiber structure abnormality, increased vascularity, rounding of nuclei and increased amount of glycosaminoglycans) was correlated to both dynamic and static signal enhancement. Two years following surgical treatment, the signal alterations showed regression of early contrast enhancement (AUC decreased from 9 preoperatively to 2 postoperatively). The clinical outcome was as follows: 8 patients excellent, 4 good, 2 fair and 1 poor. Conclusion: Patients with chronic painful achillodynia showed an early contrast-agent enhancement corresponding to the tendon lesion. Increased enhancement correlated to increased severity of tendon histopathology and patient symptoms. Two years after surgical treatment the contrast-agent enhancement decreased.
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| 10. |
- Shalabi, A, et al.
(författare)
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Eccentric training of the gastrocnemius-soleus complex in chronic Achilles tendinopathy results in decreased tendon volume and intratendinous signal as evaluated by MRI
- 2004
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Ingår i: The American journal of sports medicine. - : SAGE Publications. - 0363-5465 .- 1552-3365. ; 32:5, s. 1286-1296
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Tidskriftsartikel (refereegranskat)abstract
- Satisfactory treatment results have been reported after eccentric calf muscle strength training in patients with chronic Achilles tendinopathy. Hypothesis Magnetic resonance imaging may be a useful adjunct in the evaluation of the effect of 3 months of eccentric calf muscle strength training. Study Design Prospective cohort study. Methods Using magnetic resonance imaging, the Achilles tendons were investigated in 25 patients (16 men and 9 women) ranging in age from 28 to 70 years (median, 51 years) before and after training. Five different magnetic resonance imaging sequences were used. Tendon volume and mean intratendinous signal were calculated using a new seed-growing technique showing 99.3% and 96.6% intraobserver reliability, respectively. The clinical outcome was categorized according to pain level and performance using a questionnaire completed by the patient. Results The eccentric training resulted in a 14% (mean) decrease of tendon volume measured on T1-weighted images, from 6.6 ± 3.1 cm3 to 5.8 ± 2.3 cm3 (P < .05). The intratendinous signal in the symptomatic Achilles tendon measured on proton density-weighted images decreased 23% (mean), from 227 ± 77 signal units to 170 ± 83 signal units (P < .05). The gadolinium contrast agent-enhanced images did not add further value compared with other sequences. Clinical Outcome The clinical outcome was categorized as excellent in 10, good in 3, fair in 5, and poor in 8 patients. The [. Delta]signal correlated significantly with the pain level (P < .05). Conclusions Eccentric training resulted in decreased tendon volume and intratendinous signal and was correlated with an improved clinical outcome. Magnetic resonance imaging techniques can be used as an adjunct to clinical evaluation by monitoring morphologic effects in clinical treatment studies of Achilles tendinopathy.
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| 11. |
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| 12. |
- Shalabi, A, et al.
(författare)
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MR evaluation of chronic Achilles tendinosis. A longitudinal study of 15 patients preoperatively and two years postoperatively
- 2001
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Ingår i: Acta radiologica (Stockholm, Sweden : 1987). - : SAGE Publications. - 0284-1851 .- 1600-0455. ; 42:3, s. 269-276
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To evaluate surgically treated patients with chronic Achilles tendinosis by MR. Material and Methods: Gd-contrast-enhanced (CME) T1-, precontrast T1-, PD- and T2-weighted images were obtained preoperatively and 2 years following surgical treatment on 15 middle-aged patients with severe symptoms of chronic Achilles tendinosis. MR evaluation included the depiction of intratendinous signal alterations and their volume, and also measurement of tendon diameter. A questionnaire and clinical examination evaluated the clinical outcome. Results: The most sensitive sequence to depict an intratendinous lesion was the CME T1-WI. There was marked regress of the estimated volume of the intratendinous signal alteration from a median of 1.2 cm3 preoperatively to 0.0 cm3 postoperatively on CME T1-WI. CME T1-WI showed a regress in intratendinous signal abnormality from 13 out of 15 patients preoperatively to 4 of 15 patients 2 years postoperatively. The a.p. dimension was 9 mm at both MR occasions. The clinical outcome was excellent in 8, good in 5, fair in 1 and poor in 1 patient. Conclusion: Surgical treatment of chronic Achilles tendinosis and its healing resulted in a decrease or elimination of the intratendinous signal alteration correlating to an improved clinical outcome 2 years postoperatively.
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| 13. |
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| 14. |
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| 15. |
- Svensson, M., et al.
(författare)
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A long-term serial histological evaluation of the patellar tendon in humans after harvesting its central third
- 2005
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Ingår i: Knee Surg Sports Traumatol Arthrosc. - : Springer Science and Business Media LLC. - 0942-2056 .- 1433-7347. ; 13:5, s. 398-404
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Tidskriftsartikel (refereegranskat)abstract
- It is previously known that the patellar tendon does not normalise histologically in the short term after harvesting its central third. The aim of the study was to obtain long-term serial biopsies from the central and peripheral parts of the patellar tendon after the harvesting procedure. Our hypothesis was that in the long term after harvesting its central third, the patellar tendon does not regain normal histological appearance. Seventeen consecutive patients, who had undergone anterior cruciate ligament reconstruction using patellar tendon autografts, were included. Percutaneous biopsies were obtained under ultrasonographic guidance 27 (24-29) months and 71 (68-73) months after the index procedure, respectively. The sections were stained with haematoxylin and eosin. The biopsies were evaluated using light microscope. Both at 27 months and 71 months, the fibre structure was deteriorated and the vascularity and cellularity were increased compared with normal tendon. This was seen in both the central and peripheral parts of the tendon. In conclusion, nearly 6 years after harvesting its central third, the patellar tendon had still not normalised histologically, neither in the central nor peripheral parts of the tendon.
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